Apparatus for moistening tobacco and other products in bulk



April 29, 1958 2,832,353

F. B. DOYLE APPARATUS FOR MOISTENING TOBACCO AND OTHER PRODUCTS IN BULK Filed May 19, 1955 APPARATUS FOR MOISTENING TOBACCO AND My invention relates to a mechanism for moistening organic products in bulk and, more particularly, to moistening tobacco in hogsheads.

During the relatively long period between the time tobacco is picked and its ultimate use it is desirable, at various times, to add moisture to the product. .For example, when tobacco is aged it becomes dry and brittle and cannot be handled Without damage to the leaves. It is therefore necessary to apply moisture tothe-tobacco' to render it fit for handling in further operations.

It has been found that for the most satisfactory introduction of moisture to products in bulk it is necessary to first remove the air which permeates the product before applying the moisture to the product. This prevents incondensible air pockets in the product from blocking penetration of the moisture to the center of the cells of the products. The present method for introducing moisture to tobacco or other organic products is to'provide a relatively air-tight chamber which receives the product. Means for controllably evacuating this chamber, usually a steam evacuator, is provided to subject the product to a high vacuum. After the desired vacuum has been reached steam is added to the chamber through a separate and independent system. This system includes means to add water to the steam before introduction to the chamber to provide a steam of proper quality to achieve the desired moistening effect. "After the steam has been introduced, the chamher is again evacuated until a sufficiently low pressure is reached to cause a boiling of the moisture in the product. This boiling washes out the residual noncondensibles. The introduction of steam and evacuation is repeated until there is a uniform distribution of moisture throughout the product.

-' In addition to the moistening process, there are other processes where it is desirable to apply steam to tobacco or other organic products. For example, it is sometimes necessary to fumigate the product. The fumigant may be introduced to and removed from the product in superheated steam, using the same apparatus used for the moistening process.

Apparatus presently used in adding moisture to tobacco requires two separate systems, one for the introduction of the steam to the chamber and the other for-the evacuation process. the steaming and evacuations are accomplished with a single simple system, resulting in a corresponding reduction in piping, valves, and associated equipment. In addiltion, the apparatus of the present invention greatly facilitates operation of the steaming cycle. This is a distinct advantage to the smaller processors who can- In the present invention 5 ited States Pate titlc) introducing water not afiord a fully automatic installation and must rely on manually controlled apparatus. Another feature of the present invention is a simple, reliable means for to the steam before it enters the chamber. V I V In brief, a hermetically sealed chamber is provided to receive the tobacco orother products in bulk. The chamber is connected to a gas exhaust passage or steam evacuator system which receives a relatively high pressure steam at the upstream side. A'valve "on" the downstream side opens to the atmosphere. During the steaming operation water is introduced into the passage connecting the chamber to the steam evacuator. A pipe,

. with a valve, connected to a source of water extends into the passage with the axis at the discharge end of the pipe parallel to the axis of the passage. A needle valve in the pipe and a screen across thepassage at thepoint of entry into the chamber causes a proper mixing of the steam and water.

During the evacuating process the valve on the downstream side of the steam evacuator is opened to the atmosphere and the valve in the pipe connecting the source of water is closed. The steam passes through the evacuator system at high velocity and low pressure, drawing the air or steam out of the chamber. When the desired vacuum is reached, the valve on the downstream side of the steam evacuator is closed, preventing the exit of steam into the atmosphere. The steam received by the evacuator system is thus forced into the chamber containing the product. The Water valve is opened to supply water for mixture with the steam to provide a steam of proper quality for moistening the product. To re-evacuate the chamber, the water valve is closed and the steam evacuator valve is again opened to the atmosphere. This process is repeated until a desired uniform moisture permeates the product. Thus the steaming and evacuation process are accomplished by a single system by reversing the flow of steam through the'system and adding moisture to the steam only during the steaming process.

' It is therefore a general object of the present invention to provide a simple apparatus for introducing moi'sture to organic products, such as tobacco, in bulk.

It is another object of the present invention to provide apparatus combining in a single system means for evacuating air or steam from, and introducing steam to, a chamber receiving tobacco or other organic products.

It is yet another object of the present invention to provide a gas exhaust passage connected to a chamber containing tobacco in bulk which can be closed to apply steam to the tobacco.

It is still another object of the present invention to provide apparatus for mixing water with steam to produce steam of the proper quality for applying moisture to organic products.

,A further object of the present invention is to provide an improved system for treating organic products which selectively uses a steam evacuator for purposes of evacuation or for the purpose or introducing steam, as desired.

The novel features which I believe to be characteristic of my invention are set forth with particularity in the appended claims. My invention itself, however, both as to its organization and method of operation, together assa'ass with further objects and advantages thereof, will best be understood by reference to the following description taken in conjunction with the accompanying drawings in which:

Figure l is a side elevational view of the present invention;

Figure 2 is an enlarged view of the final stage of the steam evacuator system showing steam passing out into the atmosphere through the open valve; and

Figure 3 is the same as Figure 2 except that the valve is closed and the steam is shown being forced back through the gas discharge passage.

Construction Referring now to Figure l, a hermetically sealed or airtight chamber is provided with doors 11 and 12 at either end. The doors have sealing gaskets 13 and 14 around their edges to form air-tight seals when closed. A window 42, having an air-tight seal 43, is mounted in door 12. Containers 15, holding tobacco or other organic products to be moistened, are received within the chamber 10.

A gas exhaust passage consisting of discharge pipe 16 and the evacuator system 17 is connected to the chamber 11]. Discharge pipe 16 defines a passages between the chamber 10 and the steam evacuator system shown generally at 17. The steam evacuator system in the particular apparatus herein described comprises a first stage evacuator, shown generally at 18, an intermediate condenser 19, and a final stage evacuator, shown generally at 20.

The first stage evacuator 18 consists of a pipe having a restricted passage 21. A steam discharge pipe 23 receives steam from pipe 36 which is connected to a source of relatively high pressure steam (not shown). Pipe 23 is connected to the first stage evacuator 18 at its upstream end 18a. The admission of steam to evacuator 18 is regulated by valve 24 connected to pipe 23. Discharge pipe 16, leading to chamber 1! is connected to the first stage evacuator near its upstream end 18a. At its downstream end 181) the first stage evacuator connects to condenser 19.

The final stage evacuator is connected at its upstream end 20a to condenser 19. The construction of the final stage evacuator 20 is similar to the construction of evacuator 18, having a restricted passage 22 and a steam discharge pipe 25 receiving steam from the source of steam through pipe 36. Pipe 25 is connected to the upstream end 20:: of evacuator 20. Valve 26, connected to pipe 25, regulates the admission of steam to the final stage evacuator 20.

A shut ofi valve 34 is connected to the downstream end 20b of the final stage evacuator-2t). The outlet side of valve 34 connects to a heater which utilizes the heat of the steam discharged from the evacuator system to heat water fed to the boiler. The heater outlet 35a discharges to the atmosphere.

The condenser chamber 19 is installed on a platform 27 affixed to the top of three I beams 28 attached across the top of chamber 111. An electric motor '29, also mounted on platform 27, drives hydraulic pump 30 connected to the bottom of condenser 19. Hydraulic pump 30 is connected to the water cooling tower 31 by pipe 32. The water cooling tower 31 is installed above the condenser 19 and is connected to it by pipe 33. Valve 37 regulates the entry of water to the condenser from the water cooling tower 31.

A source of water (not shown) is connected by water pipe 33 to discharge pipe 16, which latter pipe also serves to carry the steam into chamber 10. Water pipe 33 has a valve 39 to regulate the quantity of water admitted to discharge pipe 16. A needle valve 40 is installed in water pipe 38 between valve 39 and the point where water pipe 38 enters discharge pipe 16. Inside the discharge pipe 16 water pipe 38 is bent at a 90 angle so that its discharge end 38a is parallel to the axis of pipe 16. The discharge .end 38a of water pipe 38 may either be turned up, as

Operation At the beginning of the initial evacuation of chamber 10, steam discharge valve 26 and shut off valve 34 are opened permitting steam to How from its source through the final stage evacuator 20 into the atmosphere, as shown in Figure 2. Valve 24 is then opened sending steam through the first stage evacuator 18 into the condenser. Cooling water is circulated through the condenser 19 by opening valve 37 in the line from the water cooler 31 and pumping water from the bottom of the condenser 19 to the water cooler 31 by means of hydraulic pump 30. During this process a high vacuum is created in condenser 19 by the action of the final stage evacuator 20 and by the contraction of steam entering the condenser 19 from the first stage evacuator 18. With a high vacuum at the downstream end of the first stage evacuator and with the steam under an initial pressure of at least pounds per square inch, the steam reaches a high velocity passing through the first stage evacuator 18. This causes a low pressure in the evacuator 1S and air is drawn out of chamber 10 through discharge pipe 16. During the evacuation process valve 39 in the water line is closed.

After the chamber 10 is exhausted, shut off valve 34 is closed. This stops the exit of steam from the gas exhaust passage into the atmosphere. With the exit into the atmosphere blocked and a vacuum existing in chamber 10 the steam reverses its flow through the gas exhaust passage. Steam from discharge pipe 25 is forced back into the condenser 19 as shown in Figure 3. Similarly, steam from pipe 23 (Figure 1) is drawn into discharge pipe 16. At approximately the same time that shut off valve 34 is closed, valve 37 is closed to stop entry of water into the condenser 19 from the water cooler 31. If desired, valves 34 and 37 may be operated simultaneously by electrical means (not shown) and controlled by a single controller 44 as shown diagrammatically in Figure 1.

The steam as used in the evacuation process is in a superheated state. However, the steam used to add moisture to the products in the treating chamber should be in the saturated state. Since in the present invention a single system is used having a single source of steam to both evacuate and add steam to the chamber 10, it is necessary to have controllable means in the system to add moisture to the steam when the system is operating as source of moisture for the products. This is achieved by water pipe 38 leading from a source of water (not shown), valve 39, needle valve 40, the elbow bend 38a in pipe 38, and the screen 41. Shortly after the flow of steam is reversed in the system valve 39 is opened to permit water to flow into'discharge pipe 16. Needle valve 40 acts to break up the stream of water into small droplets, creating a mist. This mist is directed through pipe bend 38a into the flow of steam in discharge pipe 16 in a direction parallel to that flow. The screen 41 is located across the passage defined by discharge pipe 16 at a point between the entry of the mist to that passage and the air-tight chamber. Thus the mist will contact the screen 41 with full impact to aid in mixing with the steam which carries it throughout the treating chamber. It has been found by experiment that for most satisfactory moistening of the product in bulk the proper quantity of water to admit through valve 39 is the minimum amount which will produce a fog in chamber 10. This condition can be observed through window 42, and valve 39 regulated accordingly.

With the'introduction of steam to the chamber, the temperature in the chamber rises. As the temperature of the vapor in the chamber approaches within 10 to 20 degrees Fahrenheit of the desired ultimate chamber temperature, which for example, would be approximately 160 degrees Fahrenheit for Burley tobacco, it is desirable to reduce the steam how to the chamber to permit a slower approach to the desired temperature. To reduce the flow of steam, valve 24 may be closed.

When the ultimate desired temperature in the chamber is reached, the re-evacuation of the chamber is begun. Initially valve 39 is closed to stop the entry of moisture into discharge pipe 16 and valve 34 is opened to permit exit of the steam into the atmosphere. Valve 37 is opened to begin circulation of water through the condenser 19. When the pressure in the chamber is reduced to about 3 inches of mercury absolute valve 24 is opened to reactivate the first stage evacuator 18. At about 2 inches of mercury absolute-valves 34 and 37 are closed and valve 39 opened to begin the resteaming process. Normally, to achieve a satisfactory uniform distribution of moisture throughout the bulk product three steamings and t ee evacuations are desirable.

The apparatus herein described is not limited in its use to the introduction of moisture to the product in bulk. It is sometimes desirable to introduce other matter to the product, such as fumigating chemicals. It may be desirable to carry this matter to the chamber in a superheated steam. The apparatus and process described herein can be used by introducing the desired chemical to the system into discharge pipe 116 in lieu of water as described in the moistening process.

While I have shown and described specific embodiments of the present invention it will, of course, be evident that various modifications and alternative constructions may be made without departing from the true spirit and scope thereof. Particularly, the present invention is not limited to the use of a two stage evacuator system as shown, but may be incorporated in a single or multi-stage system. I therefore intend by the appended claims to cover all such modifications and alternative constructions as come within their true spirit and scope.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a machine for treating organic products with steam including a source of steam at relatively high pressure and a hermetically sealed chamber to receive the organic products, the improvement comprising: means defining a gas exhaust passage from the chamber, said means including a plurality of restricted passages defining evacuators; means defining a steam condenser chamber in said passage between two of said restricted passages; means to cool said condenser chamber to condense steam therein; steam discharge pipes connected to said source and in discharge relation to the restricted passages, respectively, each pipe being oriented in the exhaust direction to efiect cumulative gas evacuation from the chamber in conjunction with the action of the condenser when normal steam fiow and condenser cooling action takes place; and a shut off valve located in the exhaust passage downstream of the plurality of evacuators, whereby when the valve is closed and the condenser not cooled the direction or steam fiow throughout the exhaust passage is reversed to introduce steam into the chamber.

2. in a machine for treating organic products with steam including a source of steam at relatively high pressure and a hermetically sealed chamber to receive the organic products, the improvement comprising: means defining a gas exhaust passage from the chamber, said means including a plurality of restricted passages defining evacuators; steam discharge pipes connected to said source and in discharge relation to the restricted passages, respectively, each pipe being oriented in the exhaust direction to effect cumulative gas ejection from the chamber when normal steam flow takes place; and a shut oil valve located in the exhaust passage downstream of the plurality of evacuators, whereby when the valve is closed the direction of steam flow throughout the exhaust passage is reversed to introduce steam into the chamber. p

3. in a machine for treating organic products with steam including a source of steam at relatively high pressure and a hermetically sealed chamber to receive the organic products, the improvement comprising: means defining a gas exhaust passage from the chamber, said means including at least one restricted passage defining an evacuator; a steam discharge pipe connected to said source and in discharging relation to the restricted passage, the pipe being oriented in the exhaust direction to eject gas from the chamber when normal steam flow takes place; a shut oif valve located in said gas exhaust passage downstream the steam discharge pipe, whereby upon valve closure the steam flow is reversed to travel through said passage and into the chamber.

4. in a machine for treating organic products having a source of steam and a relatively air-tight chamber to receive the organic products, the improvement comprising: an evacuating system having a plurality of restricted passages in a gas exhaust passage from the chamber; means defining a condenser chamber between two of the restricted passages; controllable means to cool the condenser chamber to condense the steam therein; a plurality or steam pipes from the source of steam connected to the restricted passages of the evacuating system and oriented in the discharge direction to produce an evacuation of the relatively air-tight chamber in cooperation with the condensation of the steam flowing through the condenser as cooling takes place; a shut. off valve in the evacuating system downstream of the restricted passages as steam flows during evacuation to check the flow of steam and reverse its course through the restricted passages forcing it into the air-tight chamber; and electrically operable means to close the shut 01f valve and stop the cooling of the condenser in one operation.

5. In a machine for treating organic products with steam including a source of steam at relatively high pressure and a hermetically sealed chamber to receive the organic products, the improvement comprising: means dening a gas exhaust passage from the chamber, said means including at least one restricted passage defining an evacuator; a steam discharge pipe connected to said source and in discharging relation to the restricted passage, the pipe beiug oriented in the exhaust direction to eject gas from the chamber when normal steam flow takes place; a shut-oh: valve in the gas exhaust passage downstream of the restircted passage as normal steam flow takes place to check the flow of steam and reverse its course forcing it back through the gas exhaust passage into the air-tight chamber; and means located in the path of travel of the reversed steam flow to introduce water in mist form to desuperheat the steam prior to entry into said chamber.

6. in a machine for treating organic products with steam including a source of steam at relatively high pressure and a hermetically sealed chamber to receive the organic products, the improvement comprising: means defining a gas exhaust passage from the chamber, said means including at least one restricted passage defining an evacuator; a steam discharge pipe connected to said source and in discharging relation to the restricted passage, the pipe being oriented in the exhaust direction to eject gas from the chamber when normal steam fiow takes place; and means located in said gas exhaust passage downstream of the steam discharge pipe as normal steam flow takes place to shut oil the passage and direct the steam flow into the chamber.

7. In a machine for treating organic products with steam including a source of steam at relatively high pressure and a hermetically sealed chamber to receive the organic products, the improvement comprising: means defining a gas exhaust passage from the chamber, said means including at least one restricted passage defining an evacuator; a steam discharge pipe connected to said source and in discharging relation to the restricted passage, the pipe being oriented in the exhaust direction to eject gasjfrom the chamber when normal steam flow takes place; and means located in said gas exhaust passage downstream of the steam discharge pipe as normal steam flow takes place to shut off the passage and direct the steam flow back through the gas exhaust passage into the chamber.

References Cited in the fileof this patent UNETED STATES PATENTS France June 30, 

